Mild temperatures and low interest rates spiked an increase in residential real-estate sales and listings in Iowa City this past winter, local real-estate agents say.

"We got a good start on the year because it was such a mild winter, and normally, we run into a deep freeze in December and January, and we didn't have that this year," said Mike Jensen of Lepic-Kroeger Realtors. "[The temperature] makes it different for obvious reasons. You don't want to move and go out and look at homes in that kind of weather."

Iowa City had 131 residential real-estate listings sold and roughly $28 million in sales from December 2011 to March 14. There were 103 residential listings sold and approximately $21 million in sales in the same time a year ago, said Kay Seery of the Iowa City Area Association of Realtors.

"I've been in real estate just over 28 years, and usually in cold weather months, there are not as many buyers out looking as there are in March through September," said Mark Kamps, the broker and owner of Coldwell Banker Real Estate Professionals. "I tell sellers and buyers as soon as the weather starts to warm up in February, people start looking."

Kamps said historic low interest rates have also affected sales.

Amy Henderson, senior vice president for mortgage lending at the University of Iowa Community Credit Union, said the 30-year fixed rate is 4 percent, and it has been as low as 3.75 percent in the last month.

"What the government is trying to do is keep the rates at a low rate that will make homes more affordable," she said. [The government] is trying to stimulate the economy and encourage home-buying, because that's going to help the economy."

Henderson said new home buyers and current homeowners are taking advantage of the rates. Individuals are refinancing their mortgage with the new rates.

Kamps said this past winter was one of the most active winters he has seen since President Obama's homeowners' incentive, in which first-time home owners could claim credits worth $8,000 or 10 percent of their home's value — whichever is less — on taxes.

"I would say it was one of the busier [winters], busier than it's been the last few years," Kamps said. "In Obama's first or second year when the government was offering a special buyer incentive, the market was busy, but the market dried up after the incentive ended."

Jensen said this winter's homebuyers have been a mixture of married couples, single individuals, first-time home buyers, and current homeowners.

"I've seen a little bit of everything," Jensen said. "People moving in for job location, but no particular buyers and sellers."

Jensen said there are a lot of buying opportunities in the spring.

"There is a lot of good inventory on the housing market and more coming out all the time in the spring," he said. "Later in the year, inventory can get depleted — some people take their houses off the market in November and December because of holidays."